Modern server farms or datacenters typically employ a large number of servers to handle processing needs for a variety of application services. Each server handles various operations and requires a certain level of power consumption to maintain these operations. Some of these operations are “mission critical” operations, interruptions to which may lead to significant security breach or revenue losses for users associated with these operations.
However, interruptions of AC power to datacenters can be unpredictable. In some cases, power interruptions can force a sudden shutdown and/or possibly result in data losses. Datacenters typically have back-up power (e.g., energy stored in batteries) to support power consumption during AC power interruptions. The sudden shutdown can be prevented if a datacenter maintains a certain level of backup power before an input power interruption occurs. However, it remains a challenge to improve efficiencies and reliability of back-up power systems.